The present invention relates to a dispenser device for dispensing a fluid, and more particularly, the present invention relates to such a dispenser device that includes a closure system actuated automatically whenever the dispenser device is actuated.
The closure system of the present invention is applicable to all dispenser devices for dispensing fluids, and in particular to any such dispenser device including a pump or a valve connected to a tank and actuated by actuating means such as a pusher.
In dispenser devices for dispensing fluids or in spray dispenser devices, and particularly in devices containing substances such as medicines, one of the most complicated problems to be solved is that of avoiding the risk of at least some of the fluid that is to be dispensed becoming contaminated.
In general, such a device includes a tank containing the fluid, and a dispenser member, such as, for example, a pump, inside which some quantity of fluid always remains present after each dispensing operation. That quantity of fluid remains in contact with the outside environment via the dispensing orifice or the ejection nozzle of the dispenser member, and it can thus easily be subjected to drying and/or contamination, which gives rise to the following undesirable consequences:
in the event of contamination, e.g. with bacteria, the contaminated fluid is dispensed to the user the next time the device is actuated, which is obviously dangerous to the user's health; in addition, the contamination can, in some cases, extend to the entire tank of fluid, resulting in an increased health risk; and PA1 in the event of drying, in addition to highly probable contamination, there is also a risk that the dispensing orifice of the dispenser member clogging up; this is very frequent in particular in spray dispenser devices in which the fluid passageways are usually very small. PA1 the closure member is an integral part of the spray-producing portion which, in that type of device, must be made very accurately, and must not give rise to any limitation on the free flow of the fluid; since the closure member is an integral part of said portion, it constitutes such a limitation; PA1 the closure member requires a certain amount of pressure in order to open, but before the device is used for the first time, most spray pumps are not capable of generating the required pressure; each pump is provided with a metering chamber which is also the pump chamber, and said chamber is empty when the device has not yet been used, i.e. it contains only air or an inert gas; as a result, each spray device using such a pump needs to be primed, which constitutes in actuating the device one or more times to expel the air from the chamber of the pump and to replace it with the liquid to be dispensed; the problem then encountered is that, when the pump is actuated on a gas, the pressure generated is significantly lower than the pressure obtained by pumping a liquid, so the pressure generated during priming is generally not sufficient to open the closure member; as a result, the air is not expelled and the pump is not primed so that no spray can be dispensed.
To overcome that problem, it has been proposed to use preservative agents mixed with the fluid to be dispensed. Unfortunately, when medication is to be dispensed, that solution often gives rise to side effects such as allergy problems.
To avoid that, "closure systems" have been developed in recent years so as to provide a dispenser device whose dispensing orifice can be closed in airtight manner.
Such systems do indeed solve the problem of the substance remaining in the dispenser member drying out and/or becoming contaminated. Unfortunately, they generally give rise to considerable new problems, in particular in spray applications. Such a closure system is generally actuated, i.e. opened, by means of the pressure generated by the pump when the device is actuated. That gives rise to the following adverse consequences:
Documents EP-0 031 123 and U.S. Pat. No. 3,336,000 disclose closure systems in which the closure member is opened mechanically, independently of the pressure created by the substance. However, those closure members present the same problems concerning spray applications since they form the end of the fluid flow portion and they prevent the fluid from flowing freely.